Driving mechanism for knitting needle displacement in warp knitting machines, such as raschel machines, particularly

ABSTRACT

A drive arrangement for knitting needles in warp knitting machines. In addition to the up and down motion, a tilting motion is imparted to the knitting needles with the fulcrum at the height of the casting-off edge of a stationary casting-off bar. The drive linkage comprises a crank drive whose rocker arm is connected to a link which is the carrier of the knitting needles. The carrier is rigidly connected to the link at an angle of 110* to 160*. The link has an intermediate pivotally mounted support.

[ June 24, 1975 United States Socha et a].

Patent DRIVING MECHANISM FOR KNITTING 66/86 R 66/86 R 66/86 R 3 570,2693/1971 Wenrich......... 1.. NEEDLE DISPLACEMENT IN WARP 3,587,252 6/1971Kohl............. Kohl....................................

MACHINES, PARTICULARLY.

FOREIGN PATENTS OR APPLICATIONS mt t w m 3 mm 0 9 M. t 0 r. 3G m a w 0 8MW .ah a .Mb e r O t n e V H I H 7 Attorney, Agent, or Firm-Herbert L.Lerner Y n a m r e G o 9 c m &k b i fl a Tw o mmr en Ine h h & m wmm .&e n g i S v A M 7 ABSTRACT 22 Filed: Dec. 3, 1973 121 App]. No.: 420,795

A drive arrangement for knitting needles in warp knitting machines. Inaddition to the up and down motion, Foreign Appllcauon Priority Dam atilting motion is imparted to the knitting needles Dec. 2, I972 with thefulcrum at the height of the casting-off edge of a stationarycasting-off bar. The drive linkage com-'Germany.................,.......'... 2259170 prises a crank drive whoserocker arm is connected to a link which is the carrier of the knittingneedles. The carrier is rigidly connected to the link at an angle of 110to 160. The link has an intermediate pivotally mounted support.

[58] Field of 66/86-89 [52] US. [51] Int.

References Cited UNITED STATES PATENTS 4 Claims, 4 Drawing Figures3,375,682 4/1968 Wcnrich.......;...................... 66/86 RPATENTEDJUN 24 I975 SHEET F/Gjf 1 l DRIVING MECHANISM FOR KNITTINGNEEDLE DISPLACEMENT IN WARP KNITTING MACHINES, SUCH AS RASCHEL MACHINES,PARTICULARLY The invention relates to a drive arrangement for the motionof the knitting needles in warp knitting machines, and in particular,Raschel machines, wherein in addition to the up and down motion. atilting motion is imparted to the knitting needles with their fulcrum atthe height of the casting-off edge of a stationary casting-off bar.

More particularly, the invention relates to a novel four lever linkagewhich is driven by an eccentric mounted crank arm at high speed. Thecrank arm drives a rocker arm which is pivotally mounted 'on the frame.The rocker arm is connected to and drives a link which is mounted on anarm which is pivotally mounted on the frame, the dimensions of thelinkage members are chosen so as to produce a desired compound motion ofthe knitting needles.

The tilting motion additionally imparted to the knitting needlesproduces a counter movement of the knitting needles relative to theeye-pointed needles and prevents the mass forces of the guide bars fromincreasing during the swinging motion of the guide bars. Therefore. itbecomes possible to shorten the swing of theiguide bars with a knittingmotion which is equivalent to the present knitting process.

It is already known to tilt the knitting needles about a fulcrum at theheight of the casting-off edge of the stationary casting-off barsufficiently far so that the guide bars need to execute only thedisplacement movement. In this prior device, the tilting motion isgenerated by a cam mechanism.

The disadvantage of this prior device is the cam mechanism mentioned,which presents considerable difficulties at the high machine speeds nowdesired because of the high inertial force situation.

It is further known to drive the needle bar with its knitting needlesand the casting-off bar, on the one hand, and the guide bar, on theother hand, in such a manner that these elements execute an exclusivelycounterrotating movement with opposite phase, and therefore produce thecounter movement mentioned above. A major shortcoming of thelast-mentioned device is caused by the fact that the casting-off bar isnot stationary, but participates in the swinging motion of the knittingneedles. In addition to an increase of the mass forces, the dangerexists here that the loops hanging on the needle shanks areoverstretched by several millimeters. Furthermore, the functioning oflinear guides, such as are used in the known devices, is restricted athigh machine speed due to the inertial forces that appear.

It is an object of the invention to eliminate the shortcomings describedabove in a drive arrangement for the motion of the knitting needles inwarp knitting machines and in particular, Raschel machines.

According to the invention, this problem is solved by providing that thedrive arrangement comprises a fourlever linkage which is connected to acrank, which is connected to a rocker arm, which is part of adoublerocker. The double-rocker is connected to a link which is thecarrier of the knitting needles. The carrier elements of the knittingneedles are rigidly connected with the link at an angle of l lto 160.The use of a fourlever linkage makes possible very high machine speeds.The four-lever linkage is furthermore less sensitive to dust, which canlead to jamming of devices with linear guides.

If according to a further advantageous feature of the invention, a lineconnecting the frame fulcrum of the rocker, which predominantlydetermines the tilting motion of the knitting needle, to the head of theknitting needle is approximately perpendicular to the line connectingthe two end positions of the linkage points of the rocker-link junction,the remaining movement of the needle at the casting-off edge is only afew tenths of a millimeter. Overstretching of the loops hanging on theneedle shanks is thereby avoided and a pronounced dwell at the highestpoint of the knitting needle movement is obtained.

Accordingly, a principal object of the invention is to provide new andimproved knitting machine means.

Another object of the invention is to provide new and improved knittingmachine means which provides a compound lifting and tilting motion tothe knitting needles.

Another object of the invention is to provide new and improved knittingmachine means which provides a combined lifting and tilting motion tothe knitting needles comprising a four lever linkage driven by aneccentric drive at high speed.

Other features which are considered as characteristic of the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a particular embodiment. it is nevertheless not intended to belimited to the details shown, since various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings, in which:

FIG. 1 is a side view of a drive arrangement, partly in cross section,with a knitting needle in the lowest position.

FIG. 2 is a side view according to FIG. 1, in which the knitting needleis in the uppermost position.

FIG. 3 is a motion diagram for the knitting needle and swinging motionof the guide bars, and

FIG. 4 is a polar diagram of the knitting needle motion.

FIG. 1 shows a crank drivel, comprising the main shaft 2, an eccentric2' firmly connected therewith and the connecting rod 3. The four-leverlinkage 4 consists of the rocker arms 5 and '6, mounted onframeconnected fulcrum points 7 and 8, respectively. The arms 5 and 6are connected to the link 9 at the linkage joints l0 and 11respectively. The rocker arm 5 is provided with an extension 5, whichmakes a connection with the crank drive 1 via the pin 12. The link 9also has an extension 9' mounting the carrier elements for the knittingneedles 13.

The carrier elements consist of the support post 14 firmly connected inthe extension 9 and a fastening rail 15 connected thereto, for theneedle bar 16. The mountings 17 for the knitting needles 13, which inthe embodiment shown here consist of latch needles, are tightly boltedto the needle bar 16. The stationary casting-off bar 18 is mounted nextto the knitting needle 13. The eye-pointed needles 19 of two guide bars,not shown, are shown guiding the thread above the castingoff bar 18.Mounted next to the casting-off bar 18 is the take-off cylinder for theweaved product. Elastic diaphragms 23 and 24, for protection againstdust and flying lint, are connected to the support post 14 and member21, 22 of the drive housing.

In FIG. 1 the junction point 10 has reached its end position. whichdetermines the lowest position of the knitting needle 13. FIG. 2 showsthe highest end position of the four-lever linkage 4, the junction point10, and the other, already mentioned parts. In FIG. 2, the knittingneedle 13 has reached its highest position and also the farthestexcursion of the tilting motion of the needles about an assumed fulcrumat the height of the stationary casting-off edge 18.

In FIG. I the end position of the junction point 10' reached in FIG. 2,is indicated by dash-dotted lines. It will be seen clearly that the lineconnecting the frame point 7 and the head 13' of the knitting needle 13is approximately perpendicular to the connecting line 25 between thejunction points l0, 10 in the two end positions. In FIG. 2 the angularposition of the rigid connection between the link 9 and the carrierelements for the knitting needles 13 is shown by the angle 26.

FIG. 3 shows the motion of the knitting needles 13 resulting fromtheindividual phases of the knitting process by means of a motiondiagram. The motion consists of a component in the direction x and acomponent in the perpendicular direction v as functions of rotationindicates the curve of the swing of the eyepointed needles 19. Themotion diagram shows that up to the angle of rotation a 80,corresponding to the position of the main shaft 2, the knitting needleis moved only in the direction y, i.e.. the knitting needle is movedvertically .upward. In the position a 80 the underlaying motion iscompleted. The eye-pointed needles 19 then swing in the direction towardthe head of the knitting needle. The head of the knitting needle 13 inturn moves toward the eye-pointed needles 19 be cause of the motion nowbeginning in the direction FIG. 4 shows particularly clearly the entirecycle of the resulting knitting needle motion in .r and v directions ina polar diagram.

The drive arrangement according to the invention has the alreadymentioned advantage, which is that the residual motion of the knittingneedle at the casting-off edge is only a few tenths of a millimeter andoverstretching of the loops hanging on the needle shanks is avoided.This makes additionally possible a particularly great latitude inplacing the drive with a warp knitting machine or Raschel machine. Thus,for instance, a mirror-inverted arrangement of the coupling of therocker arm 6 with the crank drive 1 producing the drive motion is alsopossible. The drive arrangement can of course, be used in addition, tolatch and point needles, also for capillary, slider or other knownneedle types.

We claim:

1. Drive means to provide a tilting motion in addition to an up and downmotion to knitting needles, comprising a crank drive, including a crankshaft, a first frame mounted rocker arm connected to the crank shaft, alink member having one end connected to the other end of said firstrocker arm. a second frame mounted rocker arm pivotally connected to anintermediate point on said link, a carrier of knitting needles rigidlyconnected to the other end of said link at an angle of 1 10 to to theaxis of said link, the lengths of said crank shaft, rocker arms and linkbeing chosen to impart an up and down motion and a tilting motion tosaid carrier.

2. Drive means according to claim I, wherein the line connecting theframe point of said rocker arm, which predominantly determines thetilting motion of the knitting needle, with the head of the knittingneedle is approximately perpendicular to a line connecting two endpositions of the junction point of the rocker arm and link.

3. Drive means as in claim I, wherein an intermediate point on said linkis pivotally mounted on a member, the other end of said member beingpivotally mounted on the frame.

4. Driver means as in claim I, wherein said crank shaft is driven by aneccentric drive.

i l l=

1. Drive means to provide a tilting motion in addition to an up and downmotion to knitting needles, comprising a crank drive, including a crankshaft, a first frame mounted rocker arm connected to the crank shaft, alink member having one end connected to the other end of said firstrocker arm, a second frame mounted rocker arm pivotally connected to anintermediate point on said link, a carrier of knitting needles rigidlyconnected to the other end of said link at an angle of 110* to 160* tothe axis of said link, the lengths of said crank shaft, rocker arms andlink being chosen to impart an up and down motion and a tilting motionto said carrier.
 2. Drive means according to claim 1, wherein the lineconnecting the frame point of said rocker arm, which predominantlydetermines the tilting motion of the knitting needle, with the head ofthe knitting needle is approximately perpendicular to a line connectingtwo end positions of the junction point of the rocker arm and link. 3.Drive means as in claim 1, wherein an intermediate point on said link ispivotally mounted on a member, the other end of said member beingpivotally mounted on the frame.
 4. Driver means as in claim 1, whereinsaid crank shaft is driven by an eccentric drive.